LAS VEGAS (AP) — Although much attention has been paid to autonomous vehicles being developed by Google and traditional car companies, one truck maker believes that automated tractor-trailers will be rolling along highways before self-driving cars are cruising around the suburbs. There are many advantages to autonomous big rigs, which use a combination of features that already are available on high-end passenger cars. Legal and philosophical questions stand in the way, as does perfecting the technology that links radar sensors and cameras to computers that can brake and accelerate the truck and handle any freeway situation. Daimler Trucks North America LLC CEO Martin Daum said society might forgive a number of deaths caused by tired truck drivers at the wheel but they would never forgive a single fatal crash blamed on a fully automated big rig.